The OP is right--this is a rich lode of dramatic material. All you really need is a room, a guy, and some technobabble. This is the idea that will undoubtedly return Star Trek to network television.

Once it's safely into season 5 and people are eager for more, I propose a spin-off: Star Trek: Holodeck Repair Guy. This is a little more ambitious. There will be two sets, the holodeck itself and the guy's quarters. In a typical episode, he's sleeping late when he gets the call that the holodeck is on the fritz. He goes down, sees what's wrong, and fixes it.

The money part is that in fixing the holodeck, he gets access to all of the programs people have been running. So if the chief engineer runs a fantasy simulation of himself and an engine designer (for example), he knows all about it; he can peep at the deepest hidden fantasies of everyone on board. As you can imagine, he becomes a quite wealthy and influential member of the crew.

The catch is that, to keep things under budget and FCC-compliant, you won't actually show any of these depraved fantasies on the show--you'll just have the HRG watching them on a small monitor, and conveying their impact through his reactions to them.